Apparatus for maintaining a diesel engine in restarting condition

Abstract

A large primary engine is maintained in readiness to start under low ambient temperature conditions by a small auxiliary engine having a liquid cooling system in parallel with the cooling system of the primary engine. Exhaust from the auxiliary engine heats the coolant circulating through the two engines in a heat exchanger. The lubricating oil from the primary engine is also heated by the auxiliary engine exhaust in the same heat exchanger. A generator driven by the auxiliary engine charges the batteries used to start the primary engine.

What is claimed is: 
     
       1. A standby system for maintaining a liquid cooled primary engine in restarting condition at very low ambient temperatures after the primary engine is shut off, the primary engine being of a type having a liquid cooling system including a radiator connected to the primary engine for normally cooling a coolant liquid circulated through the engine block and the radiator, and an expansion tank into which the coolant drains, the standby system comprising: an auxiliary engine having a liquid cooling system, a heat exchanger having at least two fluid passages therethrough for transferring heat from one fluid to another, fluid passage means including a pump, the auxiliary engine cooling system, and one passage of the heat exchanger, one end of said fluid passage means being connected to the expansion tank and the other end being connected to the outlet connection from the primary engine block to the radiator, said pump directing fluid through the primary engine block, the auxiliary engine block, and the heat exchanger in a closed path that shunts the radiator, for transferring heat from the auxiliary engine to the primary engine block, and means directing exhaust gases from the auxiliary engine through another passage of the heat exchanger.   
     
     
       2. Apparatus of claim 1 further including thermostat means for sensing the temperature of the primary engine, and means responsive to the the thermostat means for starting the auxiliary engine and said pump when the temperature of the primary engine drops below a predetermined level. 
     
     
       3. Apparatus of claim 1 further including electrical generator means driven by the auxiliary engine independently of the primary engine, battery means for starting the primary engine, and means charging the battery means from the electrical generator means. 
     
     
       4. Apparatus of claim 3 wherein the primary engine includes a lubricating oil circulating system, and means including a pump and valve means for circulating lubricating oil through the circulating system of the primary engine, the pump being driven by the generator means.